Regulation of neuroendocrine differentiation in gastrointestinal carcinoid tumor cells by notch signaling.

Context: Gastrointestinal (GI) carcinoid tumors elaborate serotonin and other vasoactive substances, causing the carcinoid syndrome. Based on developmental biology data, we hypothesized that basic helix-loop-helix transcription factors, including achaete-scute complex homolog-like 1 (Ascl1)/hASH1, and the Notch signaling pathway might regulate the neuroendocrine phenotype in GI carcinoids.

Objective: The aim of this study was to evaluate expression of developmental transcription factors and Notch signaling components in GI carcinoids and model their interaction in a relevant GI carcinoid cell line.

Opposite effects of lithium and valproic acid on trophic factor deprivation-induced glycogen synthase kinase-3 activation, c-Jun expression and neuronal cell death.

Recent studies demonstrate that lithium and valproic acid (VPA), two commonly used mood-stabilizing drugs, have neuroprotective effects against a variety of insults. Inhibition of the proapoptotic enzyme, glycogen synthase kinase-3 (GSK-3), has been suggested to be the mechanism of action of neuroprotection for both drugs. In this study, we tested if lithium and VPA could protect cultured cerebellar granule neurons (CGNs) from GSK-3-mediated apoptosis induced by trophic factor withdrawal (serum/potassium deprivation).

Expression and characterization of Gag protein of HIV-1(CN) in Pichia pastoris.

To express the core protein of HIV-1 of Chinese prevalent strain (HIV-1(CN)) in Pichia pastoris, the full-length gag gene was inserted into the secretory expression vector pHILS1. Linearized recombinant plasmid pHILGAG by SalI was electrotransformed into the yeast strain GS115, and the yeast transformants were identified by PCR. To induce the interest protein to be expressed, the PCR positive transformants were inoculated in the medium of BMGY and BMMY, mRNA of the strain was detected by RT-PCR, and the expressed protein was analyzed by SDS-PAGE, Western blotting and thin layer scanning.

DNA sequence representation without degeneracy.

Graphical representation of DNA sequence provides a simple way of viewing, sorting and comparing various gene structures. A new two-dimensional graphical representation method using a two- quadrant Cartesian coordinates system has been derived for mathematical denotation of DNA sequence. The two-dimensional graphic representation resolves sequences' degeneracy and is mathematically proven to eliminate circuit formation.

Purification and reactiongenicity of human immunodeficiency virus type 2 total external glycoprotein expressed in Pichia Pastoris.

The purification of human immunodeficiency virus type 2 total external glycoprotein gp105 expressed in Pichia pastoris was investigated. Expression conditions were optimized by an orthogonal test. The results from tests of variance analyses showed that the most important parameter for efficient expression of total gp105 in P.